Perhaps for being considered mere megakaryocyte cytoplasmic debris responsible for wound repair alone, platelets have had a secondary role when compared to other cellular blood components. However, in the last 20 years we have learned much more about these fascinating cells, which have slowly regained a prominent place in hematology. This review discusses the most outstanding and novel contributions on platelet biogenesis, its regulation by the bone marrow microenvironment and humoral factors, analyzing from megakaryocyte generation to platelet release.

RESUMO

In embedment-free transmission electron microscopy without employing epoxy embedding media, the cytoplasmic matrix, in which cell organelles and elements including the cytoskeletons are held in place, lattices of strands are clearly and constantly disclosed in every cell. Their compactness is variable in different kinds of cells and in different domains of one and the same cell, and it is changeable under hypo- or hyper-osmolarity. In addition, the appearance of strand-lattices is duplicable in artificial proteins at different sol/gel states and concentrations. All taken together, a new and probable ultrastructural criteria has been proposed for identification of cytoplasmic sol/gel states with a hope that the dynamic properties of the cell is understood not only by the cytoskeleton but also by the sol/gel states of cytosolic proteins and their concentration in distinct association with cellular ultrastructural entities.

RESUMO

Abstract The effect of alkali stress on the yield, viscosity, gum structure, and cell ultrastructure of xanthan gum was evaluated at the end of fermentation process of xanthan production by Xanthomonas campestris pv. manihotis 280-95. Although greater xanthan production was observed after a 24 h-alkali stress process, a lower viscosity was observed when compared to the alkali stress-free gum, regardless of the alkali stress time. However, this outcome is not conclusive as further studies on gum purification are required to remove excess sodium, verify the efficiency loss and the consequent increase in the polymer viscosity. Alkali stress altered the structure of xanthan gum from a polygon-like shape to a star-like form. At the end of the fermentation, early structural changes in the bacterium were observed. After alkali stress, marked structural differences were observed in the cells. A more vacuolated cytoplasm and discontinuities in the membrane cells evidenced the cell lysis. Xanthan was observed in the form of concentric circles instead of agglomerates as observed prior to the alkali stress.

Female patient, complaining of weakness and pain in hypogastric, was admitted to the emergency department of the University Hospital of the West of Paraná (HUOP). During the interview reported treatment of chronic infection with hepatitis C virus (HCV) with peginterferon and ribavirin. Among the laboratory tests ordered, the search for self-antibodies against cellular antigens, traditionally known as antinuclear factor, showed fluorescence shaped like rods and/or rings in the cytoplasm of cells. This study attempts to clarify the relationship between this pattern not yet completely understood and the clinical picture of the patient. This pattern is characterized by 3–10 µm rods or rings with 2–5 µm in diameter scattered throughout the cytoplasm of the cell. Therefore, this new standard has been designated as "rods and rings" (RR). The antigenic target of this reaction was identified as inosine-5'-monophosphate dehydrogenase type 2 (IMPDH2) which is a key enzyme in the synthesis of purine nucleotides. The IMPDH2 enzyme aggregated or modified shaped RR in those patients treated with ribavirin may become antigenic and induce an autoimmune response. It is possible that interferon alpha stimulates the occurrence of anti-RR reactivity apparently induced by ribavirin. So far it is not known why the standard RR in HEp2 cells occurs only in a fraction of patients with HCV. Previous studies presented in this paper allow affirming that these antibodies associated with the standard RR are strongly related to hepatitis C. Moreover, it can be stated that the occurrence of anti-RR reactivity is promoted by combination therapy with interferon and ribavirin.

The chikungunya epidemic in the Dominican Republic began in February 2014. During the first six months 429 421 cases were recorded, representing 65% of all those notified to the Pan American Health Organization by 33 countries and territories of the Region of the Americas. This epidemic has spread quickly in the Dominican Republic, requiring a focused intersectoral response, led by the Ministry of Public Health and involving major efforts by the National Epidemiological System and the health services network. Given that the virus will affect thousands of people, this article seeks to describe the actions that have already been carried out, and to share the results and lessons learned during these first months with health ministries and professionals in the countries of the Region, in order to assist them to prepare an appropriate response to confront the epidemic effectively and efficiently.

This is a qualitative study, using the ‘Do it yourself’ method, which aimed to analyze how Problem-Based Learning (PBL) promotes the development of learner’s autonomy in the process of learning to learn. The subjects were 16 students and two tutors involved in the discipline. Data collection techniques combined semi-structured interviews, participant observation, log in portfolios, evaluation forms, and audio recording of the tutorials. Data analysis followed interpretation strategies defined by the authors: initial and in depth readings; construction and assembly of meanings’ maps; development, description and analysis of empirical categories, in the light of the theoretical framework. The PBL favors the (re)construction of knowledge by the use of prior knowledge and experiences that are shared in small group; through the process of theorization; and by means of relevant knowledge - one that can be applied to practice. We conclude that PBL encourages continuous learning, developing in the student the autonomy in the process of learning to learn.

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Chromium pollution is produced in connection with industrial processes like in tanneries. It has been suggested that bioremediation could be a good option for clean up. The stress effect of variable chromate levels, pHs and growth temperatures on biochemical parameters of two Cr(VI) reducing bacterial strains Pseudomonas aeruginosa Rb-1 and Ochrobactrum intermedium Rb-2 was investigated. Transmission electrone microscopy (TEM) was performed to study the intracellular distribution of Cr(VI). It was observed that initial stress of 1000 µgmL-1 caused significant enhancement of all studied biochemical parameters at pH 7.0 and growth temperature of 37 °C showing great bioremediation potential of the strains. Transmission electron microscopy revealed that the distribution of chromium precipitates was not uniform as they were distributed in the cytoplasm as well as found associated with the periplasm and outer membrane. Fourier transform infrared spectroscopy showed the possible involvement of carboxyl, amino, sulpohonate and hydroxyl groups present on the bacterial cell surface for the binding of Cr(VI) ions. Cr(VI) stress brought about changes in the distridution of these functional groups. It can be concluded that the investigated bacterial strains adjust well to Cr(VI) stress in terms of biochemical parameters and along that exhibited alteration in morphology.

The applications of mesenchymal stem cells (MSCs) are becoming increasingly more promising for regenerative medicine and tissue engineering fields. MSCs can be isolated from adult animals from a variety of tissues, such as the adipose. This study focused on the isolation, culture and differentiation of MSCs from canine adipose tissue. Samples of subcutaneous adipose tissue from five dogs were collected. These cells were isolated, cultured and differentiated into osteoblasts, adipocytes and chondrocytes. We obtained 146,803 (±49,533) cells/g. Growth kinetics and viability studies were conducted during cell culture and the evaluation of cell differentiation was successfully performed by cytochemistry. The cell cultures were initiated with 20,000 MSCs/ml. Rapid growth was observed at 72 hours (220,000 cells/ml), the exponential phase between 72 and 192 hours (455,000 cells/ml) and saturation at 240 hours (355,000 cells/ml). The cellular viability ranged from 96 to 100%. MSCs in culture are fibroblastic cells, fusiform with basophilic cytoplasm and spherical nucleus. The length and width means of the cells and nuclear diameter ranged from 80.85-98.36µm, 17.40-28.79µm and 15.46-17.74µm respectively.

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The distal cytoplasmic motifs of leukemia inhibitory factor receptor α-chain (LIFRα-CT3) can independently induce intracellular myeloid differentiation in acute myeloid leukemia (AML) cells by gene transfection; however, there are significant limitations in the potential clinical use of these motifs due to liposome-derived genetic modifications. To produce a potentially therapeutic LIFRα-CT3 with cell-permeable activity, we constructed a eukaryotic expression pcDNA3.0-TAT-CT3-cMyc plasmid with a signal peptide (ss) inserted into the N-terminal that codes for an ss-TAT-CT3-cMyc fusion protein. The stable transfection of Chinese hamster ovary (CHO) cells via this vector and subsequent selection by Geneticin resulted in cell lines that express and secrete TAT-CT3-cMyc. The spent medium of pcDNA3.0-TAT-CT3-cMyc-transfected CHO cells could be purified using a cMyc-epitope-tag agarose affinity chromatography column and could be detected via SDS-PAGE, with antibodies against cMyc-tag. The direct administration of TAT-CT3-cMyc to HL-60 cell culture media caused the enrichment of CT3-cMyc in the cytoplasm and nucleus within 30 min and led to a significant reduction of viable cells (P < 0.05) 8 h after exposure. The advantages of using this mammalian expression system include the ease of generating TAT fusion proteins that are adequately transcripted and the potential for a sustained production of such proteins in vitro for future AML therapy.

RESUMO

The composition and distribution of the glycoconjugates (GCs) secreted by the epithelium of ovarian lamellae with reference to the reproductive biology of Genypterus blacodes (Schneider, 1801) through lectin hi stochemistry is here discussed. In this species, the epithelial cells that line the ovarian cavity presented sharp morphological variations along the reproductive cycle related to the mucus secretion that accompanies oocyte ma turation. During sp awning season, residues of mannose and N-acetylglucosamine were detected in the glycocalyx of those cells using lectinhistochemistry. N- acetylgalactosamine and fucose were also observed in the same zone. The greatest variations in the lectinhistochemical pattern were found in the apical cytoplasm composition in comparison to the basal zone of the cells. The results of the present study were discussed by comparing their possible functional implications.

Introduction: In liaison psychiatry it is possible to get an integral view of patient's treatment and needs, paying special attention to pharmacological interactions and contraindications. Some particular cases motivated the description, report and review about other possible applications of 5HT2A and 5HT3 antagonist, particularly Mirtazapine and Olanzapine, in hyperalgesia syndrome, tinnitus and Progressive Multifocal Leukoencephalopathy by JC virus. Method: Cases report. Results: We describe 3 cases of patients in which Mirtazapine and Olanzapine were necessary not only to control psychiatric symptoms (affective / behavioral symptoms and insomnia) but to act as adjuvant therapy in axis III diseases. The use of any drug in psychiatry must take in to account the context of the patient, the presence of comorbidity, contraindications and pharmacological interactions so as to grant a positive outcome also promoting the multidisciplinary work between specialists.

RESUMO

The aim of this study was to assess the immunohistochemical expression of p63 protein, epidermal growth factor receptor (EGFR) and Notch-1 in the epithelial lining of radicular cysts (RC), dentigerous cysts (DC) and keratocystic odontogenic tumors (KOT). For this study, 35 RC, 22 DC and 17 KOT were used. The clinical and epidemiological data were collected from the patient charts filed in the Oral Pathology Laboratory, University of Ribeirão Preto, Brazil. Immunohistochemical reactions against the p63, EGFR and Notch-1 were performed in 3-µm-thick histological sections. The slides were evaluated according to the following criteria: negative: <5% of positive cells, low expression: 5-50% of positive cells, and high expression: >50% of positive cells. Moreover, the intensity of EGFR and Notch-1 expressions was also evaluated. Fisher's exact test and Spearman's correlation coefficients were used for statistical analysis, considering a significance level of 5%. Almost all cases demonstrated p63, EGFR and Notch-1 expressions. The p63 expression was significantly higher in KOT (p<0.001). Positive correlation between these immunomarkers was observed. These findings suggest the participation of p63, EGFR and Notch-1 in the development, maintenance and integrity of cystic odontogenic epithelial lining, favoring lesion persistence. The high expression of p63 in KOT suggests that it may be related to their more aggressive biological behavior and marked tendency to recurrence.

RESUMO

Lymphangiomas are benign hamartomatous lesions of lymphatic vessels. Wilms Tumor 1 (WT1) is a transcription factor that is activated in some human neoplasias. WT1 protein expression is observed in endothelial cells during angiogenesis and is a useful marker to distinguish between vascular proliferations and vascular malformations. The purpose of the present study is to report a case series of oral lymphangiomas together with an immunohistochemical investigation of WT1. Seventeen cases of oral lymphangioma were retrieved and reviewed. Immunohistochemical analysis of WT1 protein was performed and pyogenic granuloma samples were used as positive controls. The male/female ratio was 1.125 and most of the lesions occurred in young subjects. While pyogenic granuloma showed positive staining for WT1, the endothelial cells lining the thin-walled dilated lymphatic vessels of lymphangiomas were negative for this protein. The findings strengthen the idea that oral lymphangioma is a vascular malformation characterized by lymphatic dilatation without significant endothelial proliferation.

RESUMO

Junctional devices in Sertoli cells conform the blood-testis barrier and play a key role in maturation and differentiation of germ cells. The spacial distribution of ectoplasmic specializations of Sertoli cells was studied by beta-actin immunolabelling, using laser confocal and transmission electron microscopy. For confocal microscopy, beta-actin immunolabelling of ectoplasmic specializations was studied over the background of either prosaposin or glutaredoxin immunolabelling of the Sertoli cytoplasm. Labelling was found near the basal lamina, surrounding early spermatocytes (presumably in leptotene-zygotene) or at one of two levels in the seminiferous epithelium: (1) around deep infoldings of the Sertoli cell cytoplasm, in tubular stages before spermiation, and (2) in the superficial part of the seminiferous epithelium, in tubular stages after or during spermiation. For transmission electron microscopy, beta-actin immunolabelling of ectoplasmic specializations was also used. Ectoplasmic specializations were found at two different levels of the seminiferous epithelium. We also used freeze fracture to analyze the characteristics of tubulo-bulbar complexes, a known component of apical ectoplasmic specializations. Also, these different approaches allowed us to study the complex arrangement of the actin cytoskeleton of Sertoli cells branches, which surround germ cells in different stages of the spermatogenic cycle. Our results show a consistent labelling for beta-actin before, during and after the release of spermatozoa in the tubular lumen (spermiation) suggesting a significant role of the actin network in spermatic cell differentiation. In conclusion, significant interrelations among the beta-actin network, the junctional complexes of the blood-testis barrier and the ectoplasmic specializations were detected at different stages of the seminiferous cycle.

RESUMO

Several antihistaminics possess antibacterial activity against a broad spectrum of bacteria. However, the exact mechanism of such activity was unclear. Hence, the aim of this study is to investigate their mechanism of antibacterial activity especially their effect upon the permeability of the bacterial cytoplasmic membrane. The effects of azelastine, cetirizine, cyproheptadine and diphenhydramine were studied using Gram-positive and Gram-negative multiresistant clinical isolates. Leakage of 260 and 280 nm UV-absorbing materials was detected upon treatment with the tested antihistaminics; indicative of membrane alteration. Using an artificial membrane model, cholesterol-free negatively-charged unilamellar liposomes, confirmed the effect of antihistaminics upon the membrane permeability both by showing an apparent membrane damage as observed microscopically and by detection of leakage of preloaded dye from the liposomes colorimatrically. Moreover, examination of the ultrastructure of cells treated with azelastine and cetirizine under the transmission electron microscope substantiated the detected abnormalities in the cell wall and membrane. Furthermore, the effect of pretreating certain isolates for both short and long periods with selected antihistaminics was followed by the viable count technique. Increased vulnerability towards further exposure to azelastine was observed in cells pretreated with azelastine for 2 days and those pretreated with azelastine or cetrizine for 30 days.

RESUMO

The life cycle of the protozoan Trypanosoma cruzi exposes it to several environmental stresses in its invertebrate and vertebrate hosts. Stress conditions are involved in parasite differentiation, but little is known about the stress response proteins involved. We report here the first characterization of stress-induced protein-1 (STI-1) in T. cruzi (TcSTI-1). This co-chaperone is produced in response to stress and mediates the formation of a complex between the stress proteins HSP70 and HSP90 in other organisms. Despite the similarity of TcSTI-1 to STI-1 proteins in other organisms, its expression profile in response to various stress conditions, such as heat shock, acidic pH or nutrient starvation, is quite different. Neither polysomal mRNA nor protein levels changed in exponentially growing epimastigotes cultured under any of the stress conditions studied. Increased levels of TcSTI-1 were observed in epimastigotes subjected to nutritional stress in the late growth phase. Co-immunoprecipitation assays revealed an association between TcSTI-1 and TcHSP70 in T. cruzi epimastigotes. Immunolocalization demonstrated that TcSTI-1 was distributed throughout the cytoplasm and there was some colocalization of TcSTI-1 and TcHSP70 around the nucleus. Thus, TcSTI-1 associates with TcHSP70 and TcSTI-1 expression is induced when the parasites are subjected to stress conditions during specific growth phase.

RESUMO

Cytoplasmic inclusion bodies in adrenal medullary chromaffin cells have been described in various species including humans. These inclusions are believed to be related to certain infectious, toxic and neurodegenerative diseases. No reports concerning such adrenal inclusions have been described in bovines. Adrenal glands from twenty bovines were evaluated in a retrospective study. Seven of these exhibited inclusions - three cases of rabies, two cases of chronic suppurative bronchopneumonia, one case of chronic suppurative peritonitis, and one case of gangrenous mastitis. The inclusions were present in higher numbers especially in cases of rabies and also in one case of chronic suppurative bronchopneumonia. The inclusions were intracytoplasmic, eosinophilic, rounded, single or multiple, of various sizes, strongly stained by PAS and were present in higher numbers in the external layer of the adrenal medulla. The inclusions were negative when subjected to immunohistochemistry for detection of viral antigens in the cases of rabies. Although inclusion bodies were present in adrenal glands devoid of other histological alterations, they were more abundant in cases in which the adrenal gland had other alterations. The correlation between certain diseases and the development of inclusion bodies is not known, which highlights the importance of further studies on these inclusions in adrenal glands of bovines.

OBJECTIVES: This study aimed to determine the frequency and antibody titers of nuclear dense fine and cytoplasmic patterns with possible clinical correlation. METHODS: From 2007 to 2009, the results of 2,788 autoantibody serological tests were assessed by indirect immunofluorescence (IIF) at LAC-HUSM/UFSM, using as substrate HEp-2. RESULTS: Among the analyzed samples, 1,998 of them were negative for autoantibodies. Among the positive samples (n = 790), we found 57 (7.2 percent) showing reactivity pattern described as dense fine speckled (DFS) (3.8 percent), or cytoplasmic (Cit) fluorescence (3.4 percent). In samples with standard DFS (n = 29), nine had titers of 1/160, and only one patient had autoimmune disease (AID). Among patients with titers > 1/160, only one patient did not have AID. Among samples with standard Cit (n = 27), 20 had titers of 1/160, and only eight were not associated with AID. The other seven patients with titers > 1/160 reported AID. CONCLUSION: The results confirm the value of 1/160 as the best cut-off point for defining AID presence, for any of the fluorescence assessed patterns. However, attention should be given to lower titers, especially for Cit IIF, since only 40 percent did not report the presence of AID.

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